1 files changed, 164 insertions, 0 deletions
diff --git a/src/rocksdb/table/block_based/filter_block_reader_common.cc b/src/rocksdb/table/block_based/filter_block_reader_common.cc
new file mode 100644
index 000000000..7dc49e83e
--- /dev/null
+++ b/src/rocksdb/table/block_based/filter_block_reader_common.cc
@@ -0,0 +1,164 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+
+#include "table/block_based/filter_block_reader_common.h"
+
+#include "monitoring/perf_context_imp.h"
+#include "table/block_based/block_based_table_reader.h"
+#include "table/block_based/parsed_full_filter_block.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+template <typename TBlocklike>
+Status FilterBlockReaderCommon<TBlocklike>::ReadFilterBlock(
+    const BlockBasedTable* table, FilePrefetchBuffer* prefetch_buffer,
+    const ReadOptions& read_options, bool use_cache, GetContext* get_context,
+    BlockCacheLookupContext* lookup_context,
+    CachableEntry<TBlocklike>* filter_block, BlockType block_type) {
+  PERF_TIMER_GUARD(read_filter_block_nanos);
+
+  assert(table);
+  assert(filter_block);
+  assert(filter_block->IsEmpty());
+
+  const BlockBasedTable::Rep* const rep = table->get_rep();
+  assert(rep);
+
+  const Status s =
+      table->RetrieveBlock(prefetch_buffer, read_options, rep->filter_handle,
+                           UncompressionDict::GetEmptyDict(), filter_block,
+                           block_type, get_context, lookup_context,
+                           /* for_compaction */ false, use_cache,
+                           /* wait_for_cache */ true, /* async_read */ false);
+
+  return s;
+}
+
+template <typename TBlocklike>
+const SliceTransform*
+FilterBlockReaderCommon<TBlocklike>::table_prefix_extractor() const {
+  assert(table_);
+
+  const BlockBasedTable::Rep* const rep = table_->get_rep();
+  assert(rep);
+
+  return rep->prefix_filtering ? rep->table_prefix_extractor.get() : nullptr;
+}
+
+template <typename TBlocklike>
+bool FilterBlockReaderCommon<TBlocklike>::whole_key_filtering() const {
+  assert(table_);
+  assert(table_->get_rep());
+
+  return table_->get_rep()->whole_key_filtering;
+}
+
+template <typename TBlocklike>
+bool FilterBlockReaderCommon<TBlocklike>::cache_filter_blocks() const {
+  assert(table_);
+  assert(table_->get_rep());
+
+  return table_->get_rep()->table_options.cache_index_and_filter_blocks;
+}
+
+template <typename TBlocklike>
+Status FilterBlockReaderCommon<TBlocklike>::GetOrReadFilterBlock(
+    bool no_io, GetContext* get_context,
+    BlockCacheLookupContext* lookup_context,
+    CachableEntry<TBlocklike>* filter_block, BlockType block_type,
+    Env::IOPriority rate_limiter_priority) const {
+  assert(filter_block);
+
+  if (!filter_block_.IsEmpty()) {
+    filter_block->SetUnownedValue(filter_block_.GetValue());
+    return Status::OK();
+  }
+
+  ReadOptions read_options;
+  read_options.rate_limiter_priority = rate_limiter_priority;
+  if (no_io) {
+    read_options.read_tier = kBlockCacheTier;
+  }
+
+  return ReadFilterBlock(table_, nullptr /* prefetch_buffer */, read_options,
+                         cache_filter_blocks(), get_context, lookup_context,
+                         filter_block, block_type);
+}
+
+template <typename TBlocklike>
+size_t FilterBlockReaderCommon<TBlocklike>::ApproximateFilterBlockMemoryUsage()
+    const {
+  assert(!filter_block_.GetOwnValue() || filter_block_.GetValue() != nullptr);
+  return filter_block_.GetOwnValue()
+             ? filter_block_.GetValue()->ApproximateMemoryUsage()
+             : 0;
+}
+
+template <typename TBlocklike>
+bool FilterBlockReaderCommon<TBlocklike>::RangeMayExist(
+    const Slice* iterate_upper_bound, const Slice& user_key_without_ts,
+    const SliceTransform* prefix_extractor, const Comparator* comparator,
+    const Slice* const const_ikey_ptr, bool* filter_checked,
+    bool need_upper_bound_check, bool no_io,
+    BlockCacheLookupContext* lookup_context,
+    Env::IOPriority rate_limiter_priority) {
+  if (!prefix_extractor || !prefix_extractor->InDomain(user_key_without_ts)) {
+    *filter_checked = false;
+    return true;
+  }
+  Slice prefix = prefix_extractor->Transform(user_key_without_ts);
+  if (need_upper_bound_check &&
+      !IsFilterCompatible(iterate_upper_bound, prefix, comparator)) {
+    *filter_checked = false;
+    return true;
+  } else {
+    *filter_checked = true;
+    return PrefixMayMatch(prefix, no_io, const_ikey_ptr,
+                          /* get_context */ nullptr, lookup_context,
+                          rate_limiter_priority);
+  }
+}
+
+template <typename TBlocklike>
+bool FilterBlockReaderCommon<TBlocklike>::IsFilterCompatible(
+    const Slice* iterate_upper_bound, const Slice& prefix,
+    const Comparator* comparator) const {
+  // Try to reuse the bloom filter in the SST table if prefix_extractor in
+  // mutable_cf_options has changed. If range [user_key, upper_bound) all
+  // share the same prefix then we may still be able to use the bloom filter.
+  const SliceTransform* const prefix_extractor = table_prefix_extractor();
+  if (iterate_upper_bound != nullptr && prefix_extractor) {
+    if (!prefix_extractor->InDomain(*iterate_upper_bound)) {
+      return false;
+    }
+    Slice upper_bound_xform = prefix_extractor->Transform(*iterate_upper_bound);
+    // first check if user_key and upper_bound all share the same prefix
+    if (comparator->CompareWithoutTimestamp(prefix, false, upper_bound_xform,
+                                            false) != 0) {
+      // second check if user_key's prefix is the immediate predecessor of
+      // upper_bound and have the same length. If so, we know for sure all
+      // keys in the range [user_key, upper_bound) share the same prefix.
+      // Also need to make sure upper_bound are full length to ensure
+      // correctness
+      if (!full_length_enabled_ ||
+          iterate_upper_bound->size() != prefix_extractor_full_length_ ||
+          !comparator->IsSameLengthImmediateSuccessor(prefix,
+                                                      *iterate_upper_bound)) {
+        return false;
+      }
+    }
+    return true;
+  } else {
+    return false;
+  }
+}
+
+// Explicitly instantiate templates for both "blocklike" types we use.
+// This makes it possible to keep the template definitions in the .cc file.
+template class FilterBlockReaderCommon<Block>;
+template class FilterBlockReaderCommon<ParsedFullFilterBlock>;
+
+}  // namespace ROCKSDB_NAMESPACE